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vC HE; H. ARMBRUSTER.

DYNANHC OPTONIETER. APPucATxoN FxLED1uNE21,1917.

Patented June 17, 199.

CHARLES E. H. ARMBRUsTEnoF DENVER, COLORADO.

DYNAMIC OPTOMETER:

Speccation'of Lettersatent. Patented June 17, 1919.

Application filed J une'21, 1917'.` Serial No. 176,175.

To all whom t may concern.'

Be it known that I, CHARLEs'E. H. ARM- BnUsTnR, a citizen of the United States, residing at Denver, in the countyof Denver and State of Colorado, have inventedcertain new and useful Improvements in Dynamic Optometers, of which the following is a specilication. I

This invention relates to optical instruments of the type known as dynamic Optometers, as disclosed in my application for Patent; N o. 164,497, filed April 25, 1917.

In the instrument shown and described in the above application, a series of charts bearing test-types of graduated sizes, are automatically displayed in successive order and at predetermined distances from the eye of a patient, bymovement of the instrument alongthe visual aXis of the eye, and it is the primary object of the present invention to obtain the same result -by the intermittent movement of an element-upon which a series of test types of graduated sizes are arrangedA 1n successive order.

Other objects of my invention reside 1n providing a mechanism for the automatic operation of the test-type-carrying element which combines simplicity 1n construction with practicability in use and which may be operated either manually, ory automatically by thel movement of the instrument relative to a point at which its actuative member is attached.

The above and other objects all of which will fully appear in the course of the following description, I attain my the arrangement-J of parts and combination of devices which in their preferred form, have been illustrated in the accompanying drawings in the various views of which like parts are similarly designated, and in whic Y Figure 1 is a sectional front elevation of my improved instrumen-t,

Fig. 2, a rear elevation of the same,

Fig. 3, a section' taken along the line 3 3, Fig. 2,

4 4, Fig. 3, and

Fig. 5, a section taken Fig. 4. y A

Referring to the drawings by numerical reference characters, 2 designates a handle upon which the operating mechanism of the instrument is supported and which is adapted to be held in the hand of the operator who j moves the instrument along the line of vision along the line 55,

of an tested.

The handle carries a hollow base 3 having at its upper lend a laterally projecting rim 4 surrounded by a circular flange 5 which is broken at a point at the rear of the instrument, as shown at 6 in Fig. 2, to afford access to a milled rim on the rotatingfelement which carries the succession of test-types hereinbefore referred to, for the manual operation thereof, as will hereinafter be more fully described.

The rotary element consists in the preferred construction shown in the drawings,

eye whose dynamic power is being of a wheel which is rotatably supported upon the rim 4 of the base within the flange thereof and which consists of a circular plate 7- surmounted by a cylindrical upstanding rim 8 of slightly reduced diameter.

.The edgeJ of the plate is milled to permit of the rotation of the wheel by finger-pressure through the opening provided by the break in the flange lof the supporting base, hereinbefore referred to.

The wheel is mounted upon the upper end of a spindle 9 which is rotatably fitted in a tubular sleeve -10 formed integrally below the bottom ofl the hollow base, and which is secured against longitudinal `displacement by a nut 12 screwed upon its threaded extremityk proj ecting beyond the sleeve.

The rotary element has beneath its plate and within the hollow base, a gear-wheel 13 for its connection with an operating mechanism hereinafter to be described.

The upstanding rim of the wheel has upon its inner surface a series of equidista-ntly lower end of the spaced test-types 14 of progressively increasing sizeswhich lpreferably are arranged in endless succession. e At the outer surface of the wheel are paintedfor otherwise aiiiXed, a series of num-V bers or other identification-marks 15 which correspond in relative position with the test.- I types on the inside fof the rim and'which in Fig. 4, a transverse section along the line afford access to the milledoutside of the rim 8, may be singly observed from the rear of the instrument. I y A A vertical sight-tube extendingthrough an opening in the top of the hood khas adjey cent its ends and at opposite sides, opemngsm interiorly and oppositek which faces the interior surfaee of the rimr e of the Wheel upon which the testtypesl are aiiixed.

A housing 25 connected with an opening of the sight-tube intermediate of the points at ,which the mirrors are disposed, incloses a small incandescent lamp 26 which is connected in a conveniently located electric circuit and serves to illuminate the test-type registering With the objective opening of the tube.

The tube has furthermore an opening'v 27 above the opening in the hood through which the characters on the outside of the wheel are exposed to sight, for the purpose' of illuminating the exposed character andA thereby rendering it clearly readable to the operator.

The opening is preferably snrmounted by a defiective hood 2S which isclosedby a piece of ground glass for the diffusionof the light rays. Y

In the operation of the' instrument, the wheel is intermittently rotated at prede'- termined intervals during movement of the instrument along the visual axis of the eye of a patient Whose dynamic power is being tested, by a mechanism of which a measuring tape 29 is the actuative member.

This tape is Wound upon a spring-'controlled reel 30 whichr is mounted for rotation upon a. spindle 3l Within a casing 32 which is rigidly secured to the' baseof thev instrument by means of a depending bracket 33. A sheave 34 and a pair of rollers 36 atV opposite sides of an armv 35, all mountedv on the same bracket 33, guide the tape for movement in ay substantially horizontal di'-` rection, and a pointer 3T fixed adjacent the sheave 34 coperates with the graduatedscale of the tape to designate the distance between the instrument and a point at Which the end of the tape is fastened by means of a hook 38.

The tape is provided at predetermined points with tappets 39 to intermittently rotate a transmission member which includes a pinion a0 mesh-ing with the before referred to gear-Wheel 13 of the test-type bearing element.

The transmission member furthermore includes in rigid connection With the pinion, a disk 41 having equidistant peripheral notches 42 adapted to `admit the tappets on the longitudinally moving tape, which pass through-a groove in the under side of the disk, and thereby impart an intermittent rotary movement to the pinion and the therewith operatively engaging gear-Wheel.

A iange 43 on the disk 41 has peripheral indentations arranged in correspondence with the notches 39 to receive al roller at the end of a spring-pressed arm -i: which is pivotally mounted on the base of the. instrument.

The arm serves to frictionally hold the transmission member against accidental ro tationV andv to arrest the movement of the rotary body when after each intermittent rot-ation it is released by a tappet on the longitudinally moving tape. y l

Af spring-pressed friction brake l5 pivoted on a pintle L6 which is mounted on a bracket 47 fixed at an end of the spindle 3l around which the tape-reel revolves, normally engages the adjacent side of the reel to retard its rotary movement.

The brake has athumbspiece 48 readily accessible to the hand in which the instrument is held, for the purpose of releasing the reel from the pressure of the brake Whenever this is required in the operation' of the instrument.

ln testing the dynamic lpower of the eyes it is often required to ascertain the pat-ients ability to suppress the accommodating or focusing power of the eye by fixing' it at a predetermined distance upon an object of suiici'entl size tov repress any desire to focus.

With this object in view, the series of testtype`s= on the Wheel include one which is enlarged out of proportion to the others as shown at a9 in Fig. 1 of the drawingsl The rotary element on which the testtypes are arranged has beneath its gear- WheelVv a cam 50 which is designed to trip a lever 51 When the enlarged suppression type is in register with the opening of the sighttube, and thereby lift the transmission member to separate itsI disk from the tape which operates the same.

The member is with this end in View, mounted to move upwardly on the spindle around Which it rotates and the lever which is fulcrumed upon the base of the instrament as at 52, has a bifurcated arm extending beneath the member and at the end of its opposite arm a beveled head 53- whieh is depressed by the cam against the action of a spring 54.

The lever is furthermore provided with a handle 55 extending through an opening in the bottom of the base to provide means for To measure the lag or over-accommodation of the eye under examination, for the purpose of determining the correct power of accommodation of the patient after the instrument has been moved to aj position corresponding with the pzmctwm, procvz'mum, or nearest point at which the eye can focus, the instrument is provided with a springcontrolled reel 56 upon which is wounda measuring tape 57. p

- The tape has at its free end a hook 58 for its yattachment to a retinoscopeY or other similar instrument by which the operator may measure the refractive system of the eye, and it is trained .around a roller 59 to permit of its end being moved away from the instrument in la direction corresponding with lthat of the line of vision of the patient. In testing eyes by the use of my improved instrument, the operator attaches the end of the measuring tape 29 at a point approximately in a vertical plane with the eyes of the patient.

After the patient has been subjected to what is commonly known as the distance test, by focusing `the eyes upon a distant test-type to ascertain any errors of refraction in the eyes, the operatorplaces in aV trial frame behind which the patient is positioned, lenses which correct the refractive error and thereby establish a substantially normal or errnnetropic condition of the eyes.

.The operator holding the instrument in the hand with the sight-opening 21` of the tube 20 facing the'patient, now moves away from the patient'to a point approximately forty inches distant from the trial frame, the.measurement being readily ascertained by observing the position of the graduations on the tape relative to the pointer 37.

The operator while holding the instrument in the line of vision of the patient, now moves slightly in the opposite direction and either observes the eye of the patient looking into the sight opening, by means of a .retinoscope or other instrument of the same character as is required in the objective test, or ascertains the focusing point of the eye by the subjective test through statementsl of the patient as to the clearness of thetesttypes on the wheel which are successively brought in register with the objective opening 22 of the tube 20 and reflected by the mirrors 23 and 24 to be viewed through the sight-opening v21 a-t the upper end of the tu e.A

When the instrument is brought to a positionV adjacent the pwnctum prowz'mum, the operator measures the distance between the instrumentl and the Veye of the patient andV thereby ascertains the approximate focusing point of the eye, it being observed-that the test-types on the wheel which' during Inovement vof the instrument are'automatically brought in register with the objective opening of the tube at distances from the point at which the measuring tape is attached, predetermined by the positions of thetappets on vthe same, are, as in the instrument described in the applicationfor patent hereinbefore referred to, proportioned in accordance with the lines subtendin'g the normal visual 'angle of the eyes atv corresponding distances from: the vertex thereof.

After the approximate focusing point of the eye or eyes is thus ascertained, the correct power of accommodation is determined by measuring the lag, or, in some cases, the over-accomodation ofthe eye, bystr'etching the tape 57 to which the retinoscope is attached, either rearward or forward of the instrument to the point which the operator nds by the use of the retinoscope to be the true focusing point of the patient. v

The distance between the retinoscope and the pzmctum prom'mwn previously found, is measured by observing the graduation on the tape 57 vwhich registers with a pointer 60 fixed on a bracket 6l beneath the reel- 56. Y

The operator concludes the test by advancing the instrument toward the patient to the desired reading or working distance, at which point'he corrects the vision of the patient by placing lenses in the trial frame which enable him to clearly see the test-type on the chart displayed at that distance and withvv this knowledge land the knowledge of the accommodating Vpower of. the patient, Y previously obtained, prescribes the yrequired lenses. Y Y

During movement of the instrument relative to a point at which the end of the tape is attached, the success-ive placement of the test-typesopposite the objective opening of the sight-tube is produced by the engagement of the tappets on the tape 29 with the notches of the disk 43 which effects an inter`- mittent Vrotation ofthe wheel which carries the test-types, at periods corresponding with the predetermined distances from the eye determined by the positions of the tappets on the tape.Y

The test-types exposed to view at said distances are as hereinbefore explained proportioned in'accordance with the lines subtending the normal visual angle at the same distances from the vertex thereof and it will be understood that these typesmay consist o-f'letters and words, or, in case the instrument is used to examine the eyes of children of pictorial representations.

When the wheel is turned by hand to a position in which the large or suppression'type 49 is exposed to view by registrationw-ith the objective opening of the sight-tube, theV transmissionmember is lifted through the instrumentality of the lever 51 and :therebyv placed in an inoperative or idle condition to permit of the instrument being moved back and forth while the patient focuses continu-1 ously upon the samee'hart.

The operator by observing the numbers exposed through the opening 19 of the hood, knows the particular type which is exposed to view .and by pressing the thumb against the milled edge of the wheel he may rotate the same manually to any desired position, independent of the automatieoperating mechanism. In fact under certain circumstances, this mechanism may be dispensed with and the types on the wheel exposed only at the will of the operator.

It will be understood that by manual ro- -tation of the wheel the arrangement of the series of test-types relative to the distances at which they are successively exposed, may be varied at will; that if so desired the instrument instead of being held in the hand may be mounted upon an extensible arm which is fastened to a stationary support and that other modifications in the arrangement and construction of the cooperative parts of the .instrument may be resorted to within the spirit of the invention as set forth in the following claims.

I claim- 1. In a dynamicpptometer, a hollow rotary element, having interiorly a series of test types in successive arrangement, a relatively stationary sight-tube having openings within and without said element, reflectors disposed to reflect a type registering with the inner opening, at a point of the tube opposite the other opening, and means for rotating said element to bring said types successively in register with said inner opening.

Q. In a dynamic optometer, a hollow rotary element having interiorly a series of test-types in successive arrangement, a relatively stationary sight-tube having openings within and without said element, refiectors disposed to reflect a type registering with the inner opening, at a point of the tube opposite the other opening, a lamp disposed to illuminate the type reflected by said reflectors, and means for rotating said element to bring said types successively in register with said inner opening.

3. In a dynamic optometer, a rotary wheel having an upstanding rim bearing upon its inner surface, a series of successively arranged test-types, a relatively stationary hood incasing said wheel, a sight-tube on said hood having openings within and without the same, reflectors in said tube to reflect a type registering with its inner open# ing, at a point opposite its other opening, and means for rotating said wheel to bring its types successively in register with said inner opening.

4. In adynamic optometer, a rotary wheel having an` upstanding rim bearing upon its inner surface, a series of successively arranged test-types, a relatively stationary7 hood incasing said wheel,l a sight-tube Yon said hood having openings Within. and without the same, refiectors in said tube to refleet a typeregistering withits inner open"V ing, at a point opposite its other opening, a lamp to illuminate the type reflected by said reflectors, and means for rotating said wheel to bring its types successively in register with said inner opening.

5. In a dynamic optometer, a rotary wheel having an upstanding rim bearing upon its inner surface a series of successively arranged test--types and upon its outer surface a corresponding series of identification marks, a relatively Astationary hood incasing. said wheel and having an opening to singly expose said marks, a sight tube on said hood having openings within and without the same, reiectors in said tube to reflect a type registering'with its inner opening, at a point opposite its other opening, and means for rotating said wheel to bring its types successively in register with said inner opening.

6. In a dynamic optometer, a holder, a movable element thereon bearing in successive order, a series of test types of graduated sizes, a relatively stationary part having a sight-opening through which said test-types may be singly viewed, a reel on the holder, a measuring tape on said reel, having means for the attachment of its end to a stationary support, a second reel on the holder, and a measuring tape on said second reel, having means for its attachment to a retinoscope or the like. y

7. In a dynamic optometer, a holder, a movable element` thereonbearing in succes.v sive order, a series of test-types of graduated sizes, a relatively stationary part having a. sight-opening through which said test-types may be singly viewed, a reel on the holder, a flexible actuating member on said reel, having means for its attachment to a stationary support, and a transmission member cooperative with said actuating member to move said element intermittently at predetermined distances in a movement of the holder relative to a point at which the flexible member is secured.

8. In a dynamic optometer, a holder, a rotary element thereon, bearing in successive order, a series of test-types of graduatedv sizes, a relatively stationary part having a sight-opening through which said test-types may be singly viewed, a reel on the holder, Ya flexible actuating member on said reel, having means for its attachment to a stationary support, andv a transmissionmember coperative with said actuating member to rotate said element intermittently at predetermined distances in a movement of the holder rela--V tive to' a pointl at which the iexible member is secured. f

9. -Ina dynamic optometer, a holder, a movable element thereon, bearing in succes-v sive order, ascries of test-types of graduated sizes,.a relatively stationary part havinga sight-'opening through which said test-types may be singly viewed, a reel on the holder, a flexible actuating` member onsaid reel, having means for its attachment toa stationary support, a transmission member cooperativewith said actuatingi'-member to move said element intermittently at 'predetermined distances in `a movement of the holder relative to a point at which the flexible member is secured, and means to automatically discontinue the coperative relation between said members at a determinate distance from said point in the movement of the holder.

10. In `a dynamic optometer, a holder, a rotary element thereon bearing in successive order a series of test-types of graduated sizes, a rotary transmission member having a driving connection with said element and including a peripherally notched disk, a reel on the holder, a tape on the reel, having means for its attachment to a stationary support, and tappets on said tape adapted to enter said notches for the intermittent rotation of the transmission-member by a movement of the holder relative to a point at which the tape is attached.

11. In a dynamic optometer, a holder, a rotary element thereon, bearing in successive order a. series of test-types of graduated sizes, a rotary transmission-member having a drive ing connection with said element and includ:

ing a peripherally notched disk, a reel on the holder, a tape on the reel, having means for its attachment to a stationary support, tappets on said tape adapted to enter said notches for the intermittent rotation of the transmission-member, by a movement of the holder relative to a point at which the tape is attached, and a spring-pressed device to frictionally restrict the movements of the transmission-member.

12. In a dynamic optometer, a holder, a rotary element thereon, bearing in successive order a series of test-types of graduated sizes, a rotary transmission member having a driving connection with said element and including a peripherally notched disk, a reel on the holder, a tape on the reel, having means for its attachment to a stationary support, tappets on said tape adapted to enter said notches for the intermittent rotation of the transmission-member, by a movement of the holder relative to a point at which the tape is attached, said transmission member being adjustable to move its said disk out of the path of said tappets, and means to automatically effect said adjustment at a determinate point in the movement of said element.

13. In a dynamic optometer, a holder, a

Y ing a peripherallynotched disk, a reel on theholder, a tape on y the reel, having means for its` attachment toa stationarysupport, andtappets on saidvtape adaptedvtogenter said notches for theY intermittentrotation of .the transmission-'member` by a movement of 'the'holder relative to a point at which the tape is attached, said transmission member being adjustable to move its said disk out i of the path of said tappets, a lever to eect said adjustment, and a cam on the element for the operation of the lever at a determinate point in the rotary movement of the same. v

14. In `a dynamic optometer, a holder, a movable element thereon, bearing in successive order a series of test-types or' graduated sizes, a relatively stationary part having a Sight-opening through which said test-types may be singly viewed, a reel on the holder, a measuring tape on said reel, having means for its attachment toy a stationary support, a rotary transmission 4member in driving connection with said element, and coperative devices on said tape and said member to intermittently rotate the latter at predetermined distances in a movement of the holder relative to a point at which the tape is attached.

15. In a dynamic optometer, a holder, a movable element thereon, bearing-in successive order a series of test-types of graduated sizesya relatively stationary part having a sight-openinc through Which said test-types may be s ingiy viewed, a reel on the holder,

a measuring tape on said reel having meansV for the attachment of its end to a stationary support, and a manually adjustable brake to fritlxtionally restrict the movement of Said ree 16. In a dynamic optometer, a base, a wheel rotatably mounted thereon and having an upstanding rim bearing a series of successively arranged test-types, a hood secured to said base and incasing said wheel, a sighttube on the hood having openings Within and without the same, reflectors in said tube to reflect a type registering with its inner opening at a point opposite its other opening, a reel on the base, a flexible tape on said reel, having means for its attachment to a stationary support, a rotary transmissionv mem-v ber on the base in driving connection with said element, and coperative devices on said tape and said member to intermittently ro tate the member at predetermined distances ina movement of the optometer relative to a point at which the tape is attached;

17 In a dynamic optometer, a base2 a wheel rotatably mounted thereon and having an upstanding rim bearing a series of successively arranged test-types, a hood Secured stationary support, and means for rotating to said base and inoasing said Wheel, a sightthe Wheel Within the hood.' 10 tube on the hood having openings Within and In testimony whereof IY have aixed my Without the same, reflectors in said tube to signature in presence of two Witnesses.

reflect a type registering with its inner open- CHARLES E. H; ARMBRUSTER.l ing at a point opposite its other opening, av VVitnesseS:

reel on the base, a measuring tape `on said Gr. J. ROLLANDET,-

reel, having means for its attachment to a L. RHOADES.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

